This homebrew LED coffee table is packing 65 microcontrollers and 4,092 LEDs. Why? So you can play 4-person co-op Pong of course. Note: That's a mirror under the table and not a secret passage to Wiretown.
We'd seen designs with interactive LEDs that responded to objects on the table, and they usually had around 400 LEDs...so we decided to up the ante with 10 times as many. We built the table and then decided that simple interactions were not enough, and went to work on a full-fledged game. 4-way multiplayer pong, in fact. Being geeks, we were obligated to have the game controlled using 4 Atari 2600 controllers (circa 1977). Four players sit around the table and cooperatively try to get the highest score. Score increases with each paddle hit and a new ball is introduced on hits 5, 10, 20, 30, etc.
Speaking from experience, it's never a good idea to introduce new balls into a 4-way. I've been there before, and let me tell you: when the # poles > # holes, things get awkward. Read: The new guy accused me of staring.
Hit the jump for two really awful videos of the table in action.